1. Field of the Invention
This invention relates to a clamp holder. More particularly, this invention relates to a clamp holder for the preliminary fixing of a diametrically expanded hose clamp on a hose portion expected to be clamped at its joint with a pipe.
2. Description of the Related Art
It has hitherto been usual to carry out a pipe joining process for joining a rubber hose, etc. to a hard pipe and fixing their joint tightly with a hose clamp, as will be described below by way of example. A hose clamp 2 held in a diametrically expanded form by a stopper pin, etc. is fitted about a pipe 1 beforehand, as shown in FIG. 1A. Then, a hose 3 is joined with the pipe 1, and the hose clamp 2 is moved and positioned about their joint, as shown in FIG. 1B. Then, the hose clamp 2 is released from its diametrically expanded form to fix the joint tightly at a selected point. This method has, however, been low in working efficiency, since it necessitates the steps of moving the hose clamp and positioning it accurately in a busy pipe joining process. It has also been a useless effort to have to affix a clamp positioning mark on the hose for the accurate positioning of the hose clamp.
Therefore, the work becomes efficient if sub-assembly is carried out for the preliminary fixing of a diametrically expanded hose clamp on a hose portion expected to be clamped. A process for joining a hose to a pipe is completed only if a step of e.g. removing a stopper pin is taken to release the hose clamp from its diametrically expanded form after joining the hose.
U.S. Pat. No. 5,675,871, for example, discloses a clamp holder 6 as shown in FIG. 2. The clamp holder 6 has a base plate 4 adapted to engage the outer peripheral surface of a hose clamp and ring-shaped arms 5 for holding a hose. After the clamp holder 6 is fitted about the outer periphery of the hose clamp 7 in its diametrically expanded form, the hose 8 is inserted axially therethrough, as shown in FIG. 3. The arms 5 hold the hose 8 for the preliminary fixing of the hose clamp 7 on that portion of the hose 8 which is expected to be clamped.
U.S. Pat. No. 5,820,166 discloses a clamp holder 13 as shown in FIG. 4. The clamp holder 13 comprises a C-shaped curved base plate 10 adapted to engage the outer peripheral surface of a hose clamp 9 and having engaging projections 11 and sharp projections 12 formed on its inner peripheral surface. The base plate 10 has its gap widened to force the clamp holder 13 radially into engagement about the outer periphery of the hose clamp 9 fitted on a selected portion of a hose 14. The projections 11 are engaged in the openings or slots 15 of the hose clamp 9 to assemble the clamp holder 13 with the hose clamp 9, as shown in FIG. 5. At the same time, the sharp projections 12 engage positively with the outer peripheral surface of the hose 14 to fix the hose clamp 9 preliminarily on that portion of the hose 14 which is expected to be clamped.
JP-UM (utility model application)-A-5-87391 discloses a clamp holder 16 as shown in FIG. 6. The clamp holder 16 is a substantially semi-circular curved leaf spring and has positioning members 17 and 18 formed at its opposite ends. The positioning members 17 and 18 are engaged in the openings or slots of a hose clamp 19 to assemble the clamp holder 16 with the hose clamp 19. At the same time, the positioning members 17 and 18 engage tightly with the outer peripheral surface of a hose 20 to fix the hose clamp 19 preliminarily on that portion of the hose 20 which is expected to be clamped.
JP-A-2001-141154 discloses a clamp holder 21 as shown in FIG. 7. The clamp holder 21 has an attachment base 23 having projections 22 adapted to engage in the openings or slots of a hose clamp and a pair of arch-shaped arms 24 formed along the attachment base 23. The arms 24 have arcuately curved legs terminating in outwardly standing guides 25. The clamp holder 21 is pushed in the direction of the guides 25 and assembled with the hose clamp 27 held in its diametrically expanded form and having a hose 26 passed therethrough, as shown in FIGS. 8A and 8B. As a result, the arch-shaped arms 24 extend over the hose clamp 27. The arcuate legs of the arms 24 hold the hose 26, so that the hose clamp 27 may be preliminarily fixed on that portion of the hose 26 at which it will be clamped.
According to U.S. Pat. No. 5,675,871, the hose 8 is held by the C ring-shaped arms 5 extending about a circumferential range of 270° or more in a form of sub-assembly. Therefore, there is no fear of the clamp holder 6 slipping off the hose 8. It is, however, necessary to insert the hose 8 axially through the clamp holder 6 and hose clamp 7 put together. The problem is that the ring-shaped arms 5 are somewhat smaller in diameter than the hose 8 and make it impossible to insert the hose 8 easily.
Moreover, the force with which the hose clamp 7 is held in position on the hose 8 is weak, since it relies upon the frictional resistance between the arms 5 and the hose 8. The contact of the clamp holder 6 or the hose clamp 7 with another object is likely to cause the displacement of the hose clamp 7. Such displacement is particularly likely to occur as rotation around the hose, though it may also occur along the hose. In either event, such displacement usually requires troublesome correction in a pipe joining process.
According to JP-A-2001-141154, only the hose clamp 27 is inserted about the hose 26 beforehand and the clamp holder 21 is forced diametrically into engagement about the hose clamp 27 and the hose 26. Therefore, their sub-assembly is easy. The force with which the hose clamp is held in position on the hose 26 is, however, not strong enough, since it relies upon the frictional resistance produced when the hose 26 is held by a pair of arch-shaped arms 24. Moreover, the arch-shaped arms 24 projecting over the hose clamp 27 and the outwardly standing guides 25 formed at the ends of the arch-shaped arms 24 are likely to cause the displacement, etc. of the hose clamp 27 by contacting another object.
According to U.S. Pat. No. 5,820,166, the C-shaped curved base plate 13 is adapted to combine with the hose clamp 9 and hold it in position on the hose 14. Therefore, the base plate 13 is required to have a sufficiently large spring strength not to slip off the hose 14, while the sharp projections 12 engage so strongly with the hose 14 as to damage it. Moreover, the sharp projections 12 protrude outwardly (toward the opening of the base plate). Therefore, the sharp projections 12 damage the outer periphery of the hose 14 when the base plate 13 is forced into engagement with the hose clamp 9 and the hose 14. Moreover, the sharp projections 12 are not satisfactory for preventing any rotational displacement of the hose clamp 9, since all of a total of four projections 12 are directed outwardly and engage with only the upper half portion of the hose 14.
The device of JP-UM-A-5-87391 is similar to the invention of U.S. Pat. No. 5,820,166, but differs from it in having instead of the sharp projections 12 the positioning members 17 and 18 adapted to make surface contact with the hose 20. This makes it possible to avoid damage to the hose 20, but also weakens the force with which the hose clamp is held in position on the hose 20. Moreover, it appears from the combination of the hose clamp 19 and the clamp holder 16 as put together that the positioning members 17 and 18 of the clamp holder 16 come off the hose clamp 19 easily in a form of their sub-assembly. If they are so designed as not to come off easily, they are likely to interfere with the tightening of the hose clamp 19 in a pipe joining process and it is, therefore, undesirably essential to remove the clamp holder 16 in a pipe joining process.